fix(export_douyin_cookie): read USERNAME from os.environ in embedded python

The shell passed USERNAME as an environment variable to the embedded python heredoc (USERNAME=$USERNAME python3 ...), but the python block referenced USERNAME as if it were already a local variable. The result was NameError on every run, so the export script could never produce a cookies/<platform>_<account>.json file.

Fix: read the env var explicitly with os.environ.get('USERNAME', '') at the top of the embedded block, then use the local USERNAME as before.

export_douyin_cookie.sh

@@ -52,6 +52,9 @@ import os
 import uuid
 import sys
 
+# Shell 把 USERNAME 作为环境变量传过来, Python 需要显式取
+USERNAME = os.environ.get('USERNAME', '')
+
 DEBUG_PORT = 9222
 if USERNAME:
     COOKIE_FILE = f"cookies/douyin_{USERNAME}.json"